1. Field of the Invention
The invention relates to an intelligent subscriber identity card selection method, and more particularly to an intelligent subscriber identity card selection method for automatically determining a subscriber identity card having an optimal radio access technology (RAT) to provide optimal communications services.
2. Description of the Related Art
The term “wireless”, normally refers to an electrical or electronic operation, which is accomplished without the use of a “hard wired” connection. “Wireless communications”, is the transfer of information over a distance without the use of electrical conductors or wires. The distances involved may be short (a few meters for television remote controls) or very long (thousands or even millions of kilometers for radio communications). The best known example of wireless communications is the cellular telephone. Cellular telephones use radio waves to enable an operator to make phone calls to another party, from many locations world-wide. They can be used anywhere, as long as there is a cellular telephone site to house equipment that can transmit and receive signals, which are processed to transfer both voice and data to and from the cellular telephones.
There are various well-developed and well-defined cellular communications technologies. For example, the Global System for Mobile communications (GSM) is a well-defined and commonly adopted communications system, which uses time division multiple access (TDMA) technology, which is a multiplex access scheme for digital radio, to send voice, data, and signaling data (such as a dialed telephone number) between mobile phones and cell sites. Furthermore, the GSM also uses frequency division multiple access (FDMA) technology. The CDMA2000 is a hybrid mobile communications 2.5G/3G (generation) technology standard that uses code division multiple access (CDMA) technology. The UMTS (Universal Mobile Telecommunications System) is a 3G mobile communications system, which provides an enhanced range of multimedia services over the 2G GSM system. The Wireless Fidelity (Wi-Fi) is a technology defined by the 802.11b engineering standard and can be used for home networks, mobile phones, and video games, to provide a high-frequency wireless local area network.
With the advanced development of wireless communications technologies, it is now possible to provide multiple wireless communications services using different or the same communications technologies in one mobile station (MS). In order to provide an optimal communications services, an intelligent subscriber identity card selection method requests are provided.